Field of the Invention
The present invention relates to vehicle-wheel bearing devices with sensors, which include load sensors for detecting load on bearing portions of wheels.
Description of Related Art
As a technique for detecting load on each wheel of an automobile, a vehicle-wheel bearing with a sensor has been suggested which detects load, based on strain on an outer diameter surface of an outer ring of a vehicle-wheel bearing, by the strain being detected by a strain gauge attached to the outer diameter surface of the outer ring (for example, Patent Document 1). Further, a calculation method for estimating load acting on a wheel based on output signals from a plurality of strain sensors provided in the wheel has been suggested (for example, Patent Document 2).